1. Field of the Invention
The present invention relates to liquid preparations containing oxidation hair dyes and more particularly relates to a means and method of stabilizing liquid preparations containing oxidation hair dyes.
2. Description of Related Art
Liquid oxidation hair dye preparations contain hair dye precursors and a cosmetic carrier suitable for application to hair. The carriers preferably used are either cream-like emulsions of the water-in-oil type or aqueous or aqueous-alcoholic solutions of soaps. Oxidation hair dye bases in the form of liquid, aqueous or aqueous-alcoholic soap solutions have the desirable property of forming a thickly liquid to gel-like, ready-to-use hair dyeing preparation after adding an aqueous oxidizing developer solution.
It is also known that water-soluble cationic polymers may be added to hair dyeing preparations to condition and improve the cosmetic properties of the hair.
However, difficulties are involved in producing liquid preparations of oxidation hair dyes containing soaps and cationic polymers because these preparations tend to be inhomogeneous and, in some cases, can become cloudy, separate and/or form a sediment, resulting in the gradual loss of their hair-conditioning properties due to the interaction of the cationic polymer with the soap. On the other hand, oxidation hair dye preparations based on liquid, aqueous or aqueous-alcoholic soap solutions are very desirable because, after addition of the aqueous oxidizing developer, they form thickly liquid to gel-like dye preparations which can easily adhere to the hair after application. Accordingly, there has been a need in the art for a suitable formulation enabling soaps and cationic polymers to be incorporated in hair dye bases of this type.